1. Field of the Invention
The present invention relates to an ink jet recording head of an ink jet recording apparatus and a method for manufacturing the ink jet recording head of the ink jet recording apparatus, and more particularly to an on-demand type ink jet recording head of the ink jet recording apparatus and a method for manufacturing the on-demand type ink jet recording head, wherein the ink jet recording head ejects a series of ink droplets from its nozzles onto a recording medium in response to printing data inputted to the ink jet recording apparatus, so that the thus ejected ink droplets form desired characters, patterns or images on the recording medium.
2. Description of the Art
Heretofore, an ink jet recording head of a Kyser system has been known as one of conventional ink jet recording heads.
The Kyser system ink jet recording head (hereinafter referred to simply as a conventional ink jet recording head) is shown in FIG. 15. As is clear from FIG. 15, the conventional ink jet recording heed is substantially constructed of: ink reservoir 1; a plurality of pressure generating chambers 2 which are arranged side-by-side in a direction perpendicular to the paper, wherein each of the chambers 2 assumes an elongated shape; a plurality of ink supply ports 3 for supplying ink from the ink reservoir 1 to the pressure generating chambers 2; a plurality of vibrating plate portions 4, wherein each of the vibrating plate portions 4 defines or forms a bottom plate portion of each of the pressure generating chambers 2, and serves to change each of the pressure generating chambers 2 in volume in response to printing data inputted to a conventional ink jet recording apparatus provided with the conventional ink jet recording head; a plurality of piezoelectric actuators 5, wherein each of the piezoelectric actuators 5 is disposed adjacent to each of the vibrating plate portions 4 and serves to vibrate each of the vibrating plate portions 4; a plurality of ink erection nozzles 6, wherein each of the ink ejection nozzles 6 communicates with each of the pressure generating chambers 2 to eject ink from the pressure generating chambers 2 therefrom in response to the printing data; and, a plurality of nozzle communicating ports 7, wherein each of the nozzle communicating ports 7 provides fluid communication between each of the pressure generating chambers 2 and each of the ink ejection nozzles 6.
Ink is supplied from an ink cartridge (not shown) to each of the ink ejection nozzles 6 of the conventional ink jet recording head through fluid passages. These fluid passages are constructed of the ink reservoir 1, the ink supply ports 3, the pressure generating chambers 2, the nozzle communicating ports 7, and the nozzles 6 in this order. On the other hand, the piezoelectric actuators 5 are combined with the vibrating plate portions 4 to form a vibration system for generating pressure waves in the above-mentioned fluid passages.
In the conventional ink jet recording head having the above construction, in printing operations, the piezoelectric actuators 5 are energized to rapidly displace the vibrating plate portions 4, and thereby rapidly changing the pressure generating chambers 2 in volume, whereby pressure waves are generated in the above fluid passages. When the pressure waves are in their pressure-increasing phase, a small amount of ink is pushed out of the pressure generating chambers 2 through the ink ejection nozzles 6 to become ink droplets 8 ejected onto the recording medium (not shown) such as a sheet of paper or the like, and thereby forming desired dots on the recording medium. Formation of such dots on the recording medium is repeated in response to the printing data to form the desired characters, patterns or images on the recording medium.
The conventional ink jet recording head having the above construction is disclosed in Japanese Patent Application Laid-Open No. Hei8-58089, wherein the conventional ink jet recording head is constructed of a plurality of its component plates varying in cavity patterns. As shown in FIG. 16, component plates of the conventional ink jet recording head include a nozzle plate 6a, a reservoir plate 1a, a supply port plate 3a, a pressure generating chamber plate 2a, a vibrating plate 4a, and piezoelectric actuators 5 which are stacked vertically in this order and bonded to each other using an adhesive to form the conventional ink jet recording head.
The nozzle plate 6a is provided with a plurality of ink ejection nozzles 6 which are arranged in a row or staggered along an appropriate straight line. On the other hand, the reservoir plate 1a is provided with: a cavity for forming an ink reservoir 1; and, ports forming part of a nozzle communicating ports 7. The supply port plate 3a is provided with ink supply ports 3 and ports forming part of the nozzle communicating ports 7. The pressure generating chamber plate 2a is provided with a plurality of cavities for forming a plurality of pressure generating chambers 2 each of which assumes an elongated shape. These pressure generating chambers 2 are arranged side-by-side in a direction perpendicular to their longitudinal axes, wherein the longitudinal axis of etch of the pressure generating chambers 2 horizontally extends in FIG. 16. On the other hand, the vibrating plate 4a is partitioned into a plurality of vibrating plate portions 4 each of which forms a bottom plate portion of each of the pressure generating chambers 2.
In fabricating the conventional ink jet recording head by connecting the above-mentioned various types of component plates with each other, for example, according to a method disclosed in Japanese Patent Application Laid-Open No. Sho57-91274, a liquid adhesive film is applied to each of opposite surfaces of a desired one of the component plates through a transfer printing process or an ordinary printing process, and thereby preparing an adhesive layer having a thickness of, for example, several xcexcm. After completion of formation of the adhesive layer, these component plates are successively stacked vertically in a stack and bonded to each other under pressure to produce the conventional ink jet recording head.
At this time, in stacking vertically these component plates coated with the adhesive layers 9 (FIG. 17) in the stack under pressure, the adhesive layers 9 tend to flow out of their applied areas under the influence of pressure to enter an interior of each of the ink reservoir 1, the nozzle communicating ports 7 and the ink ejection nozzles 6. Occurrence of such flowing out of the adhesive layers 9 results in the following problem. Namely, as shown in FIG. 17, for example, in bonding the reservoir plate 1a to the supply port plate 3a, when the pressure applied to the reservoir plate 1a, and supply port plate 3a and/or the thickness of the adhesive layers are excessively large, an excess adhesive layer 10 tends to extrude into interiors of the nozzle communicating ports 7. Such extrusion of the excess adhesive layer 10 into the interiors of the nozzle communicating ports 7 increases friction losses in ink flow, which impairs smooth ejection of ink droplets 8 from the intended nozzles 6, or increases interference between the nozzles 6 to cause accidental ejection of ink droplets 8 from the nozzles 6 not intended.
Consequently, in order to prevent the above problem, Japanese Patent Application Laid-Open No. Hei5-330067 discloses a prior art teaching a means for permitting an excess amount of an adhesive layer to escape into a plurality of escape grooves 13 without occurring any problem, wherein: as shown in FIG. 18, the means is constructed of a plurality of nozzle grooves 12 and the plurality of the escape grooves 13 both of which nozzle grooves 12, and escape grooves 13 are formed in a flow passage plate 11. In this prior art, in bonding a drive plate (not shown) to the flow passage plate 11 using an adhesive 14 which has been applied to the entire surface of the flow passage plate 11 or of the drive plate (not shown) to form the adhesive layer, an excess amount of the adhesive 14 is capable of escaping into the escape grooves 13. Due to this, the amount of the adhesive 14 flowing into an interior of each of the nozzle grooves 12 may be reduced. As a result, it is possible for the conventional ink jet recording heat of this prior art to be stabilized in ink erection characteristics, and thereby improved in productivity in yield.
Further, the escape grooves 13 also may sometimes serve to function as air escape passages for permitting air trapped in a plate connection portion between adjacent component plates of the conventional ink jet recording head to escape into the atmosphere or outside.
However, in the prior art disclosed in the Japanese Patent Application Laid-Open No. Hei5-330067, as described above, the escape grooves 13 are provided essentially for a purpose of permitting the excess amount of the adhesive 14 having been applied to the entire surface of the flow passage plate 11 or of the drive plate (not shown) to escape from any critical area of the conventional ink jet recording head. In other words, the escape grooves 13 are not provided for the purpose of permitting the air trapped in the plate connection portion to escape into the atmosphere or outside. Consequently, in the prior art, the escape grooves 13 are often filled with the excess amount of the adhesive 13, and therefore often prevents the air trapped in the plate connection portion from escaping into the atmosphere or outside.
Presence of such air trapped in the plate connection portion impairs the plate connection portion in air-tightness. In other words, the presence of such air trapped in the plate connection portion prevents the plate connection portion from being brought into close contact with any one of the component plates of the conventional ink jet recording head. Further, since the air trapped in the plate connection portion increases or decreases in volume when subjected to a heating process step or a cooling process step during a stacking process of the component plates in which stacking process the component plates are stacked vertically in a stack and bonded to each other to form the conventional ink jet recording head, the adhesive layer is often separated from the corresponding component plates in use, which is called xe2x80x9cpeeling-offxe2x80x9d of the adhesive layer and considerably impairs the conventional ink jet recording head in mechanical strength.
In a case in that the conventional ink jet recording head according to this prior art is constructed of three or more of the component plates stacked vertically in a stack and bonded to each other, even when the escape grooves 13 function to permit the air trapped in the plate connection portion to escape from the plate connection portion ino the atmosphere or outside, as shown in FIG. 16, it is not preferable to form these escape grooves 13 in each of the vibrating plate 4a, the supply port plate 3a and the nozzle plate 6a since a provision of the escape grooves 13 in the vibrating plate 4a, supply port plate 3a and nozzle plate 6a all of which are thin in thickness considerably impairs the vibrating plates 4a, supply port plate 3a and nozzle plate 6a in mechanical strength. Due to this, it is necessary for the conventional ink jet recording head to form the escape grooves 13 in opposite surfaces of each of the reservoir plate 1a and the pressure generating chamber plate 2a which are sandwiched between nozzle plate 6a and supply port plate 3a and between supply port plate 3a and vibrating plate 4a, respectively. However, since an area in which the escape grooves 13 are effectively arranged is limited, there is a danger that the escape grooves 13 are formed in opposite surfaces of a portion of each of the reservoir plate 1a, and pressure generating plate 2a, which portion is considerably impaired in mechanical strength due to a presence of the escape grooves 13 closely formed in such portion even when each of the reservoir plates 1a and pressure generating plate 2a is relatively thick in thickness.
Further, in the conventional ink jet recording head, since the adhesive layer is applied to the entire surface of the flow passage plate 11, there still is danger of some inevitable protrusion of an excess amount of the adhesive layer into the nozzle grooves 12 even when the adhesive is strictly controlled in quantity.
In view of the above, it is an object of the present invention to provide an ink jet recording head and a method for manufacturing a same, which are capable of: preventing an adhesive layer from protruding into any one of cavities for forming an ink flow passage system; and, permitting air (voids) trapped in a plate connection portion to easily escape from the plate connection portion to the atmosphere, whereby the ink jet recording head is stabilized in its ink ejection characteristics, and an improved yield in productivity.
According to a first aspect of the present invention, there is provided an ink jet recording head wherein including: a nozzle plate provided with a nozzle through which ink is ejected; one or more of fluid passage plates which include at least one pressure generating chamber for pressurizing the ink and further include a plurality of cavities for forming an ink flow passage system defined by one or more of the fluid passage plates; a vibrating plate for defining a sealed portion of the pressure generating chamber; a piezoelectric actuator for pressurizing the ink of the pressure generating chamber by displacing the vibrating plate, wherein the piezoelectric actuator is connected with a portion of the vibrating plate corresponding in position to the pressure generating chamber; a plurality of adhesive layers, wherein each of the adhesive layers is inserted between adjacent plates of the nozzle plate, the fluid passage plates and vibrating plate to stack all the plates in a stack forming the ink jet recording head, an improvement wherein:
of the one or more of the fluid passage plates, at least one of the fluid passage plates is provided with an air passage for permitting air trapped in a plate connection portion between any adjacent ones of all the plates to escape out of the plate connection portion into the atmosphere when the ink jet recording head is manufactured; and
the air passage is constructed of a plurality of groove portions intermittently provided in a vicinity of an edge of at least one of the plurality of cavities for forming the ink flow passage system in each of opposite surfaces of a corresponding one of the plates, wherein the air passage formed in one of the opposite surfaces of the corresponding plate and that formed in the other of opposite surfaces are offset from each other in a plane of the corresponding plate, and communicated with each other through a through-hole to permit the air trapped in the plate connection portion to flow alternately through the air passage of the one of the opposite surfaces of the corresponding plate and that formed in the other of the opposite surfaces, thereby permitting the air trapped in the plate connection portion to escape into the atmosphere.
In the foregoing, a preferable mode is one wherein the air passage provided in the vicinity of the edge of at least one of the pluraluty of cavities for forming the ink flow passage system in the corresponding plate extends to a side edge portion of the corresponding plate.
Also, a preferable mode is one wherein the corresponding plate is provided with an atmosphere communicating through-hole; and, the air passage provided in the vicinity of the edge of at least one of the plurality of cavities for forming the ink flow passage system in the corresponding plate extends to an edge portion of the atmosphere communicating through-hole.
Also, a preferable mode is one wherein each of the groove portions which forms the air passages and disposed in the vicinity of the edge of at least one of the plurality of cavities for forming the ink flow passage system is spaced apart from the edge of the cavity by a distance of from equal to or more than 100 xcexcm to equal to or less than 600 xcexcm.
Further, a preferable mode is one wherein an adhesive layer is inserted between adjacent ones of the plates in a peripheral portion of each of the cavities for forming the ink flow passage system.
Also, a preferable mode is one wherein the peripheral portion of the cavity for forming the ink flow passage system is within a range of from equal to or more than 100 xcexcm to equal to or less than 600 xcexcm from the edge of the cavity.
Also, a preferable mode is one wherein number of the plates for forming the ink flow passage system is an odd number more than three, wherein the plates for forming the ink flow passage system are provided with the plurality of the cavities which vary in function and shape, and all the cavities are combined with each other to form the ink flow passage system; and, an odd-numbered one or more of the plates for forming the ink flow passage system as counted from a side of the nozzle plate or from a side of the vibrating plate are provided with one or more air passage.
Also, a preferable mode is one wherein a first one of the plates for forming the ink flow passage system as counted from the nozzle plate is constructed of a reservoir plate stacked on others of the plates for forming the ink flow passage system, wherein the reservoir plate is provided with one of the cavities, which one forms an ink reservoir for storing the ink therein, the reservoir plate being further provided with an axial part of a nozzle communicating port through which the pressure generating chamber is communicated with the ink ejection nozzle to permit the ink to be supplied to the ink ejection nozzle; a second one of the plates for forming the ink flow passage system as counted from the nozzle plate is constructed of a supply port plate which is provided with an ink supply port and remaining axial part of the nozzle communicating port, wherein through the ink supply port the ink reservoir is communicated with the pressure generating chamber to permit the ink to be supplied to the pressure generating chamber; a third one of the plates for forming the ink flow passage system as counted from the nozzle plate is constructed of a chamber plate provided with one of the plurality of cavities, which one forms the pressure generating chamber; each of the first and the second one of the plates for forming the ink flow passage system is provided with one or more of the air passages; and, the first, the second and the third one of the plates for forming the ink flow passage system are stacked vertically in the stack in this order.
Also, a preferable mode is one wherein the through-hole is formed into a frustoconical shape having a larger one of its opposite end openings directed toward a source of ultraviolet radiation.
Further, a preferable mode is one wherein one of the adhesive layers is sandwiched between: a surface of one of the plates for forming the ink flow passage system, in which a surface of the larger one of the opposite end openings of the through-hole is formed; and, a surface of a corresponding one of the plates, which the corresponding one is disposed adjacent to the one of the plates; and, the one of the adhesive layers is a thermosetting adhesive layer capable of being cured when subjected to ultraviolet radiation.
Still further, a preferable mode is one wherein the through-hole is formed in an area spaced apart from the edge of the cavity for forming the ink flow passage system by a distance within a range of from equal to or more than 100 xcexcm to equal to or less than 600 xcexcm; and, the thermosetting adhesive layer is applied to the area within a range of from equal to or more than 100 xcexcm to equal to or less than 600 xcexcm from the edge of the cavity for forming the ink flow passage system.
According to a second aspect of the present invention, there is provided a method for manufacturing an ink jet recording head including: a nozzle plate provided with ink ejection nozzles through which ink is elected; one or more of fluid passage plates which include at least one pressure generating chamber for pressurizing the ink and further include a plurality of cavities for forming an ink flow passage System defined by one or more of the fluid passage plates; a vibrating plate for defining a sealed portion of the pressure generating chamber; a piezoelectric actuator for pressurizing the ink of the pressure generating chamber by displacing the vibrating plate, wherein the piezoelectric actuator is connected with the vibrating plate""s portion corresponding in position to the pressure generating chamber; a plurality of adhesive layers, wherein each of the adhesive layers is inserted between adjacent plates of the nozzle plate, the fluid passage plates and the vibrating plate to stack all the plates into a stack forming the ink jet recording head, wherein at least one of the one or more of the fluid passage plates is provided with an air passage for permitting air trapped in a plate connection portion between any adjacent ones of all the plates to escape out of the plate connection portion to the atmosphere when the ink jet printing head is manufactured, wherein the air passage is constructed of a plurality of groove portions intermittently provided in the vicinity of an edge of at least one of the cavities for forming the ink flow passage system in each of opposite surfaces of a corresponding one of the plates, wherein the air passage formed in one of the opposite surfaces of the corresponding plate and that formed in the other of opposite surfaces are offset from each other in a plane of the corresponding plate, and communicated with each other through a through-hole to permit the air trapped in the plate connection portion to flow alternately through the air passage of the one of the opposite surfaces of the corresponding plate and that formed in the other of the opposite surfaces, thereby permitting the air trapped in the plate connection portion to escape to the atmosphere, the method including the steps of:
intermittently providing a plurality of groove portions in each of opposite surfaces of at least one of the one or more of the flow passage plates so as to be disposed in the vicinity of an edge of at least one of the cavities for forming the ink flow passage system, wherein the groove portions are staggered in arrangement not to have their front groove portions aligned with their rear groove portions in cross section, wherein the front groove portions are communicated with the rear groove portions through a through-hole to form the air passage; and
permitting the air trapped in the plate connection portion to escape from the connection portion when the plates are stacked vertically in a stack.
In the foregoing second aspect, a preferable mode is one wherein: in fabricating at least one of the one or more of the flow passage plates, a plurality of the through-holes are provided in opposite surfaces of at least one of the flow passage plates in a manner such that the through-holes are disposed in the vicinity of the edge of at least one of the plurality of cavities for forming the ink flow passage system; and, the plurality of the groove portions connect adjacent ones of the through-holes with each other, and are arranged not to align with each other in cross section of at least one of the flow passage plates to form the air passage for permitting the air trapped in the plate connection portion between the adjacent ones of all the plates to escape out of the plate connection portion to the atmosphere when the plates are stacked vertically in the stack.
Also, a preferable mode is one wherein a plurality of the through-holes are intermittently provided in one of opposite surfaces of at least one of the one or more of the flow passage plates in a manner such that the through-holes are disposed in the vicinity of the edge of at least one of the cavities for forming the ink flow passage system; a plurality of the through-holes are intermittently provided also in the other of the opposite surfaces of the at least one of the one or more of the flow passage plates in a manner such that each of the through-holes extends between corresponding rear surfaces of adjacent ones of the groove portions formed in the one of the opposite surfaces, wherein a plurality of the through-holes are formed in portions where the groove portions formed in the one of the opposite surfaces are aligned with those formed in the other of the opposite surfaces in cross section of the at least one of the flow passage plates, and thereby forming the air passages; and, the air passage permit the air trapped in the plate connection portion between the adjacent ones of all the plates to escape out of the plate connection portion to the atmosphere when the plates are stacked vertically in the stack.
Preferably, the air passage formed in the vicinity of the edge of the at least one of the cavities for forming the ink flow passage system in the corresponding plate extends to a side edge portion of the corresponding plate.
Also, a preferable mode is one wherein the air passage formed in the vicinity of the edge of the at least one of the cavities for forming the ink flow passage system in the corresponding plate extends to a side edge portion of the corresponding plate.
Also, a preferable mode is one wherein the air passage formed in the vicinity of the edge of the at least one of the cavities for forming the ink flow passage system in the corresponding plate extends to an edge portion of the atmosphere communicating through-hole.
Also, a preferable mode is one wherein each of the groove portions which form the air passage is spaced apart from the edge of each of the cavities by a distance of more than 100 xcexcm.
Also, a preferable mode is one wherein: in the step of intermittently providing the groove portions in the opposite surfaces of the at least one of the flow passage plates to form the air passage, opposite surfaces of the corresponding plate are simultaneously subjected to a half etching process called a xe2x80x9cdouble-side half etching processxe2x80x9d, so that the plurality of the groove portions are intermittently formed in the opposite surfaces of the corresponding plate in a manner such that the groove portions formed in one of the opposite surfaces are offset from the groove portions formed in the other of the opposite surfaces in cross section of the corresponding plate; and, the through-holes are formed in portions where the groove portions formed in the one of the opposite surfaces are aligned with the groove portions formed in the other of the opposite surfaces in cross section of the corresponding plates, and thereby forming the air passages in the corresponding plate.
Also, a preferable mode is one wherein the opposite surfaces of the corresponding plate are simultaneously subjected to the double-side half etching process, whereby both the cavities for forming the ink flow passage system and the air passage are simultaneously formed in the corresponding plate.
Also, a preferable mode is one wherein, when adjacent ones of the plates are stacked together in bonding them to each other, the adhesive layer is applied to a peripheral portion of each of the cavities for forming the ink flow passage system between the adjacent ones of the plates.
Also, a preferable mode is one wherein the peripheral portion of each of the cavities is spaced apart from the edge of each of the cavities by a distance of equal to or more than 100 xcexcm, provided that the distance does not exceed a value of 600 xcexcm at maximum.
Also, a preferable mode is one wherein number of the plates for forming the ink flow passage system is an odd number more than three, wherein the plates for forming the ink flow passage system are provided with the plurality of the cavities which vary in function and shape, and all the cavities are combined with each other to form the ink flow passage system; and, an odd-numbered one or more of the plates for forming the ink flow passage system as counted from a side of the nozzle plate or from a side of the vibrating plate which is not counted are provided with one or more of the air passages.
Still further, a preferably:
a first one of the plates for forming the ink flow passage system as counted from the nozzle plate is constructed of a reservoir plate stacked on others of the plates for forming the ink flow passage system, wherein the reservoir plate is provided with one of the cavities, which one forms an ink reservoir for storing the ink therein, the reservoir plate being further provided with an axial part of a nozzle communicating port through which the pressure generating chamber is communicated with the ink ejection nozzle to permit the ink to be supplied to the ink ejection nozzle; a second one of the plates for forming the ink flow passage system as counted from the nozzle plate is constructed of a supply port plate which is provided with an ink supply port and remaining axial part of the nozzle communicating port, wherein through the ink supply port he ink reservoir is communicated with the pressure generating chamber to permit the ink to be supplied to the pressure generating chamber; a third one of the plates for forming the ink flow passage system as counted from the nozzle plate is constructed of a chamber plate provided with one of the cavities, which one forms the pressure generating chamber; each of the first and the second one of the plates for forming the ink flow passage system is provided with one or more of the air passages; and, the first, the second and the third one of the plates for forming the ink flow passage system are stacked vertically in the stack in this order.
Also, a preferable mode is one wherein the through-hole is formed into a frustoconical shape having a larger one of its opposite end openings directed toward a source of ultraviolet radiation.
Further, a preferable mode is one wherein one of the adhesive layers is sandwiched between: a surface of one of the plates for forming the ink flow passage system, in which a surface of the larger one of the opposite end openings of the through-hole is formed; and, a surface of a corresponding one of the plates, which corresponding one is disposed adjacent to the one of the plates; and, the one of the adhesive layers is a thermosetting adhesive layer capable of being cured when subjected to ultraviolet radiation.
Still further, a preferable mode is one wherein the through-hole is formed in an area spaced apart from the edge of the cavity for forming the ink flow passage system by a distance within a range of from equal to or more than 100 xcexcm to equal to or less than 600 xcexcm; and, the thermosetting adhesive layer is applied to the area within a range of from equal to or more than 100 xcexcm to equal to or less than 600 xcexcm from the edge of the cavity for forming the ink flow passage system.
As described above, since the adhesive is applied to only a narrow limited area, there is substantially no excess adhesive in the plate connection portion between any adjacent ones of all the component plates of the ink jet recording head, and, therefore there is substantially no danger that: the extrusion of the adhesive layer in to each of the ink ejection nozzles from the plate connection portion causes interference between the individual ink ejection nozzles, and increases friction losses in ink flow. Further, in addition to the fact that the adhesive is applied to only such narrow limited area, since various types of the cavities which form the ink flow passage system are provided in the opposite side portions of the adhesive layer together with the groove portions and the through-holes both of which form the air passages, any bubble of air (void) which is apt to be trapped in the plate connection portion may escape from the plate connection portion to the atmosphere through the ink flow passages and the air passages.
Further, since each of the air passages runs along the front surface and the rear surface of the corresponding component plate alternately in a zigzag manner, it is possible for the ink jet recording head to remove any bubble of air from the front surface and the rear surface of the individual component plate without tail.
In addition, since it is not required for the air passages to be separately provided in the front surface and the rear surface of the corresponding component plate of the ink jet recording head, there is no danger that such corresponding component plate is impaired in mechanical strength.
Further, when the through-hole is formed into a frustoconical shape having a larger one of its opposite end openings directed toward a source of ultraviolet radiation in a condition in which a component plate forming the other smaller end opening of the through-hole is bonded to another component plate disposed adjacent thereto through an adhesive layer of a thermosetting adhesive which is capable of being cured when subjected to ultraviolet radiation, it is possible to further improve the plate connection portion in air-tightness.
Consequently, it is possible to further improve the ink jet recording head both in air-tightness and in mechanical strength. Due to this, the ink jet recording head of the present invention is remarkably stabilized in ink ejection characteristics (recording quality), which results in yield-enhancement of the ink jet recording head in production.